For drinking water pipelines there are descriptions e.g. in DVGW data sheet W 334 of how accumulations of air can cause considerable dynamic pressure changes as a result of the different densities of the two media.
Regular servicing and maintenance of a drinking water network pays off. This is also one of the reasons why the urban area of Feldkirchen in the Federal State of Carinthia is particularly anxious to replace their ageing pipes or pipelines whose dimensions no longer correspond to current requirements.
Manholes and covers of water supply networks are designed so that they can be easily opened by the water supplier’s operating personnel, for example to operate gate valves, hydrants and other fittings.